Assistant cylinder for steam-engines.



No.' {384.510. PATENTED APR.14, 1908.

L. D. LOVEKIN, v ASSISTANT CYLINDER POE STE-AM ENGINES. APPLICATION FILED NOV.16, 1906.

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THE NoRms PETERS co., WASHINGTON, n. c.

No. 884,510.A PATBNTED APR. 14, 1908.

' L; 11. LOVEKIN.

ASSISTANTCYLINDER POR STEAM ENGINES.

APPLICATION FILED 1T()V. 16,v 1903.

' I B SHEETSTSHEBT El i-` I z 1 j( Il l i l ce n No. 884,510. PATBNTED APR. 14, 1908.

, L. D. LOVEKIN. i ASSISTANT CYLINDER FOR STEAM BI\IGIN1E`.S.`

APPLICATION FILED NOV. 16, 1906.

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misi-zml@ i No. 884,510.

LUTHER D. LOVEKIN, OF PHILADELPHIA, PENNSYLVANIA.

ASSISTANT CYLINDER FOR STEAM-ENGINES.

Specification of Letters Patent.

Application filed November 16, 1906.

Patented April 14, 1908.

Serial No. 343,712.

T o all 'whom 'it may concern:

Be it known that I, LUTHER D. LovEKIN, of the city and county of Philadelphia, State of Pennsylvania, have invented an Improvement in Assistant Cylinders for Steam-Engines, of which the following is a specifical tion.

My invention relates to assistant cylinders for steam engines and consists of certain im rovements which are Jfully set forth in the fol owing specification and shown in the accompanying drawings which form a part thereof.

The object of my invention is to provide a steam engine having reci rocating parts with an assistant cylinder or relieving the valve gears and operating mechanism of losses in power caused by gravity or inertia and weight combined and thereby increasing the eiiiciency of the engine as well as reducing the wear on the moving parts comprising the valve operating mechanism.

My invention preferably comprises a valve chest, bonnet and assistant cylinder combined in one piece, the same being arranged on the top of the valve chest and immediately over the valve, combined with a double piston moving in the assistant cylinder and connected with the valve, the said pistons being so constructed and combined with ports in the assistant cylinder that steam may pass directly from the valve chest under the larger piston during the upper portion of its movement and be automatically cut 0E by the smaller piston to insure compression during the lower portion of the movement of the said larger piston.

My invention also consists of an assistant cylinder having two piston diameters, the larger of which is provided with an annular steam channel at a short distance Jfrom the top and connecting ports through the wall of the cylinder to the u per part thereof, and the smaller of which iameters is provided with an annular ort opening into the space at the bottom oiP the larger diameter, combined with a double piston adapted to the cylinder, the larger of which pistons operates in the larger diameter of the cylinder and the smaller of which pistons o erates in the smaller diameter of the cylinc er.

My invention further consists of the combination with the valve chest of a steam engine, of an auxiliary or assistant cylinder having two distinct cylinder bores of difierent diameters combined with a differential piston adapted to said bores and in which the smaller piston o crates as a valve to control the admission o steam to the larger cylinder and its piston and also as a means of sealing the escape of steam from the larger cylinder into the valve chest during the time of compression.

My invention also comprehends various other features of construction which, together with those above speciiied, will be better understood by reference to the drawings, in which: y

Figure 1 is a sectional elevation of the upper part of the valve chest and valves of a steam engine with my im rovements Aapplied thereto; Fig. 2 is an enlarged sectional view of the assistant cylinders shown in Fig. 1; Fig. 3 is a cross section on line 3-3 of Fig. 2; Fig. 4 is a cross section on line 4-4 of Fig. 2; Fig. 5 is a sectional elevation of a modified form of my assistant cylinder 5 and Fig. 6 is a cross section on line 6--6 of Fig. 5.

Referring to Figs. l and 2, A is the valve chest and B are the main valves which are operated by any suitable valve gear such as is customary in reciprocating valves. C is the assistant cylinder and is provided with a circular ilange C which is bolted flush with the top plate of the valve chest. The lower portion of the assistant cylinder projects down below the plate C as at C2 and terminates in a cylinder D of small bore. The parts C2 and I) extend well down into the valve chest. E is the large diameter or part of the assistant cylinder and is arranged above the small diameter or part D and the greater part of it extends upward above the flange C. This large part E may have its eXtreme upper end enlarged in diameter as at E and is closed by a cylinder head F2. Arranged below the large diameter E of the cylinder and surrounding the upper part of the cylinder of small diameter D, is a well or chamber F which is provided with a series of ribs or webs F connecting the upper part D of the cylinder of small diameter with the main body wall C2 of the casting. In addition to being bored out, the small cylinder D is also cut transversely across forming an annular steam passage G at a considerable this manner the two parts D D of the small cylinder are separated by the steam passage, but are connected in one integral casting by means of the aforesaid webs F. The upper large cylinder E is also provided with an annular port H which is connected with a second annular port H higher up by means of vertical ports h. I is the piston for the larger cylinder, J is the piston for the smaller cylinder, and K is the piston rod connected to these pistons I and J and extending down through the cylinder D to the main valve B. The piston rod K is of considerably smaller diameter than the bore of the cylinder D so that the steam may freely pass from the valve chest A through the cylinder D and by port G into the cylinder E, except when the piston J is lowered sufficiently to act as a valve to close the port G. The piston I and the piston J, are preferably formed with packing rings so as to make them steam tight whereby they act as excellent piston valves for controlling the ports G, H and H.

When the piston I descends so as to uncover the port H it will cover the port H but during the uncovering of the port H and the covering of the port H there will be a short interval of timewhen steam may pass from below the piston through the ports H and H" into the cylinder part E above the piston. The relative arrangement of the pistons I and J are such that when the piston I just closes the port H in its downward movement the piston J just reaches the port G, so that there is full pressure of steam passing through the port G under the piston I during its descent. The further descent of the pistons I and J with the main valve causes the sealing of the port G and therefore the compression of the steam within the cylinder E and the well F and beneath the descending piston I, 'said compression acting to support .the gravity load and also compensate for the inertia of the moving parts under certain conditions. During the compression of the steam under the cylinder I the communication between the steam chest and the cylinder E is securely out off by the piston J which, owing to its acking rings, makes a tight joint and thereby insures perfect compression of the inclosed steam within the assistant cylinder.

In the upward movement of the parts, the compressed steam first acts upon the large piston and is assisted by the action of the live steam in the valve chest acting upon the lower face of the small piston J. As these pistons rise, the port G will be first uncovered and will admit full pressure of steam into the cylinder E slightly before the port H is uncovered, so that when the port H begins to be uncovered by the piston I, the steam under full pressure rushes through the port H, thence through ports h and finally through port H into the large cylinder E above the piston I. As soon as the piston I fully opens the port H it will have closed the port H and from then on its upward stroke will be cushioned against the steam confined above the piston. The lifting tendency of the assistant cylinder will be due to the difference in pressures below the pistons I and J and pressure above the piston I. The ports h and I-I are so located and so coperate with as takes place, drains to the bottom of the well F and passes freely through the port G into the valve chest, so that all external pipes and valves, heretofore em loyed in connection with assistant cylinc ers, are entirely avoided.

When the piston I is descending, the steam above the piston will be expanding and Conf tinue to expand until the piston commences to open the port H. When the port H opens, live steam momentarily passes above the piston, but during this time the port H is in the act of being closed and when closed, the further descent of the piston is affected by the expansion of the steam above it and subsequently by the compression of the steam below it for the remaining travel of the piston in the cylinder.

It is evident that the changing of the positions of the ports H H will produce a variation in the expansion in the down stroke as well as a variation in the compression in the up stroke. By simply varying the positions of the ports H and H it is possible to modify or change the compression or expansion. Moreover, it is evident that the port H may extend directly into the upper chamber E of the cylinder by removing the upper plugs and omitting the port H entirely. In this case, however, there would be no compression of steam above the piston I after the port H was opened but the movement of the piston would be resisted by the high pressure steam between the piston and the head of the cylinder. This modification is shown in Fig. 5. In the construction shown in Fig. 5 the general features are the same as in Fig. 2 except for the port H, but the shape of the lower part C2 is perhaps not as desirable as that shown in Fig. 2.

It will be observed that my improved assistant cylinder receives its supply of steam from its own valve chest or receiver and consequently requires no piping or valves whatever, thereby embodying simplicity of construction. It is entirely automatic in its action and has the least parts possible to secure the desired results. yIt 1s designed in such a manner that the circular or annular steam inlet port at the lower part serves the purpose of admitting steam from its own receiver and also as an automatic drain for removing any water that might collect in the lower part of the cylinder. The upper end of the cylinder is designed to secure the best results in each individual case, but the requirements of the different cases must be previously determined by the theoretical diagrams which determine whether no compression at the top is required or otherwise and what compression is required on the down stroke. The condensation from the upper part of the cylinder is drained through the ports controlled by the large piston and passes into the lower part of the assistant cylinder from which it descends through the lower port G into the steam chest below.

The iston structure, as will be seen, is of the di erential type, the diameter ofthe lower or smaller piston being determined by the velocity of steam necessary at the inlet ort G of the assistant cylinder. Both the arger and the smaller pistons have packing rings of the usual form and of such width as is necessary for riding over the narrow slotted ports in the upper and lower `cylinders. The conditions of admission and compression are designed for each individual case in order to balance the forces due to inertia and gravity and consequently these will vary with every steam engine and such variations must be taken into consideration when designing the assistant cylinder for any particular engine.

There is no exhaust pipe whatever and consequently the only steam used in connection with my improved assistant cylinder is the amount necessary to make up the losses due to radiation and condensation, and therefore the greatest efficiency possible in a device of this character is secured. As the cylinder may be lagged or packed with magnesia or any other refractory non-conductor as shown at c in Fig. 5, losses by radiation and condensation may be reduced to a minimum.

A feature of my invention resides in the construction whereby I am enabled to provide a movable steam tight packing in the lower cylinder and also employ in the lower cylinder bore a length greater than the travel of the main valve.

While I prefer the constructions shown as good practical examples of my invention, it is to be understood that the details may be modified Without departing from the spirit of the invention.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is

1. An auxiliary or assistant cylinder for a valve of a steam engine consisting of a cylinder E having annular ports H, H and connecting ports h, a piston I working in the cylinder and controlling the ports, a cylinder and piston valve for controlling the direct supply of steam from the valve chest to the cylinder E, and a connection between the piston E and the valve of the steam engine.

2. An assistant cylinder for steam engine valve and gear, consisting of a cylinder body having a bore of large diameter above and-a bore of small diameter below the latter opening into the valve chest and said cylinder having a steam port through the wall of the bore of small diameter for supplying steam to the larger and upper part and a steam port or ports through the wall of the bore of large diameter for supplying steam from the lower part to the upper part of said bore of large diameter, combined with a differential piston structure connecting with the main valve of the steam engine having a large diameter adapted to the bore of large diameter and for controlling the port therein and a small diameter adapted to the bore of small diameter for controlling the port therein and said piston diameters being so formed that the port in the bore of small diameter remains open until after the port in the bore of large diameter is closed and is then closed.

3. The combination with the valve chest of a steam engine of an assistant cylinder having a large diameter bore terminating at its lower part in a well and a small diameter bore the lower portions being arranged within the valve chest and provided with a steam port through its side wall, combined with pistons for said large and small bores of the cylinder connected together and to the main valve of the steam engine so as to move as a unit, said piston of small diameter controlling the steam from the valve chest to the large diameter bore and the piston of large diameter controlling the passage of steam from below to above it to regulate its action.

4. The combination with the valve chest of a steam engine, of an assistant cylinder having an upper cylinder part of large diameter above the valve chest and a lower Acylinder part of small diameter extending down into the valve chest and having a length substantially equal to the valve stroke, said cylinder parts being supplied with steam from the valve chest and the large cylinder part receiving steam through the small cylinder part, and a differential piston structure connected with the main valve and adapted to the two cylinder parts, whereby steam enters the cylinders only through the cylinder part of small diameter.

5. The main valve and its valve chest, combined with an assistant cylinder comprising two bores of differentdiameter in which the larger is above the smaller and each are greater in length than the travel of the valve and a differential piston structure adapted to the two bores of the cylinder and connected to the main valve and in which the smaller piston and cylinder control the steam admitted to the large cylinder.

A cylinder structure for an assistant cylinder consisting of a cylinder body having a ilange and well, combined with a cylinder bore of large diameter above the well and flange, and a cylinder bore of small diameter below the llange and having communication with the lower part of the well by a port through its side wall and below its top.

7. The valve and valve chest of a steam engine, combined with an assistant cylinder comprising a lower small cylinder within the chest and having open communication therewith and provided with a steam port through its side between its top and bottom, and an upper large cylinder directly above the small cylinder and receiving steam through the port in the small cylindei1 and having a port at the bottom and the other of which partsV extends upward within -the well and is supported by webs extending from the well wall so as to form an annular steam port through the lower cylinder into the well.

9. In assistant cylinder structure, the cylinder body having an upper cylinder of large diameter provided with an annular steam port in its wall and upwardly extending ports to a higher portion of the cylinder and also provided at the bottom with a well, combined with a two-part lower cylinder of small diameter one of which parts extends downward below the well and is open at the bottom and the other of which parts extends upward within the,we]l and is supported by y 10. An auxiliary or assistant cylinder for a valve ol' a steam engine having a large diameter and a downwardly extending lower tubular part opening into the valve chest and also having a steam port through its side wall below its top for supplying steam to the large diameter, combined with a piston for the large diameter connected with the main valve and having a downwardly extending cylindrical or piston part operating in the downwardly extending tubular'part to form a valve between the valve chest and the large diameter part of the cylinder.

l1. An auxiliary or assistant cylinder for a valve of a steam engine having a large diameter terminating in a well and a downwardly extending lower tubular part opening below.

the well into the valve chest and also having a steam port through its side wall below its top for supplying steam to the large diameter and allowing escape of water of condensation fromthe well, combined with a iston for the large diameter connected with t e main valve and having a downwardly extending cylindrical or piston part operating in the downwardly extending tubular part to form a valve between the valve chest and the .large diameter part of the cylinder to control admission of steam and escape of condensation.

12. The main valve and its chest, combined withan assistant cylinder comprising two bores of different diameter in which the larger is above the smaller and each is provided with an independent port or ports intermediate of its ends, and a differential piston structure adapted to the two bores of the cylinder and connected to the main valve and controlling said orts.

In testimony of w 'ch invention, l have hereunto set my hand.

LUTHER D. LOVEKIN.

Witnesses:

R. M. KELLY, R. M. HUNTER. 

